摘要
通过一路灯照明工程实例,探讨了路灯配电系统中的单相接地保护灵敏度校验、保护设置、接地型式选择等问题。路灯的保护应包括两级:配电线路干线保护和灯具短路保护,在TN-S系统中,路灯配电干线开关可选用B类断路器,在TT系统中,可选用RCD或其组合电器。每个灯具处宜设置短路保护,TN-S中可选用熔断器,在TT系统中,当接地电阻值较大时,可选用RCD作灯具的短路保护。路灯不宜采用TN-C系统,可考虑采用II类绝缘设备。
The paper discusses sensitivity check of single phase earthing protection fault, protection setting, earthing type selection in road lighting power distribution system through a road lighting project example. Protection of road lighting includes 2 grades： protection of main line and luminnaire short-circuit protection. Protective devices of main line may select class B circuit-breaker in TN-S system, and select RCD or its composed devices. Each luminnaire should set short-circuit protection if possible, protective devices can select fuse in TN-S system, and RCD in TT System with big earthing resistance. Road lighting power distribution system should not adopt TN- C system. Class Ⅱ insulation luminnaire may be takes, into consideration.
出处
《建筑电气》
2007年第2期30-35,共6页
Building Electricity
